#   计算器可以进行基础运算（加、减、乘、除）被除数不为零
first = float(input("请输入第一个数:"))
second = float(input("请输入第二个数:"))
operator = input("请输入运算符:+ - * /:")
if operator == '+':
    print(first+second)
elif operator == '-':
    print(first-second)
elif operator == '*':
    print(first*second)
elif operator == '/':
    if second == 0:
        print("除数不能为零")
    else:
        print(first/second)
